/*
 * Copyright (c) 2005, 2006, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.tools.javac.api;

import java.io.File;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.Writer;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Collections;
import java.util.EnumSet;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Set;

import javax.lang.model.SourceVersion;
import javax.tools.DiagnosticListener;
import javax.tools.JavaCompiler;
import javax.tools.JavaFileManager;
import javax.tools.JavaFileObject;

import com.sun.source.util.JavacTask;
import com.sun.tools.javac.file.JavacFileManager;
import com.sun.tools.javac.main.JavacOption;
import com.sun.tools.javac.main.JavacOption.OptionKind;
import com.sun.tools.javac.main.Main;
import com.sun.tools.javac.main.RecognizedOptions;
import com.sun.tools.javac.main.RecognizedOptions.GrumpyHelper;
import com.sun.tools.javac.util.Context;
import com.sun.tools.javac.util.Log;
import com.sun.tools.javac.util.Options;
import com.sun.tools.javac.util.Pair;

/**
 * TODO: describe com.sun.tools.javac.api.Tool
 * 
 * <p>
 * <b>This is NOT part of any supported API. If you write code that depends on
 * this, you do so at your own risk. This code and its internal interfaces are
 * subject to change or deletion without notice.</b>
 * </p>
 * 
 * @author Peter von der Ah\u00e9
 */
public final class JavacTool implements JavaCompiler {
	private final List<Pair<String, String>> options = new ArrayList<Pair<String, String>>();
	private final Context dummyContext = new Context();

	private final PrintWriter silent = new PrintWriter(new OutputStream() {
		public void write(int b) {
		}
	});

	private final Main sharedCompiler = new Main("javac", silent);
	{
		sharedCompiler.setOptions(Options.instance(dummyContext));
	}

	/**
	 * Constructor used by service provider mechanism. The correct way to obtain
	 * an instance of this class is using create or the service provider
	 * mechanism.
	 * 
	 * @see javax.tools.JavaCompilerTool
	 * @see javax.tools.ToolProvider
	 * @see #create
	 */
	@Deprecated
	public JavacTool() {
	}

	/**
	 * Static factory method for creating new instances of this tool.
	 * 
	 * @return new instance of this tool
	 */
	public static JavacTool create() {
		return new JavacTool();
	}

	private String argsToString(Object... args) {
		String newArgs = null;
		if (args.length > 0) {
			StringBuilder sb = new StringBuilder();
			String separator = "";
			for (Object arg : args) {
				sb.append(separator).append(arg.toString());
				separator = File.pathSeparator;
			}
			newArgs = sb.toString();
		}
		return newArgs;
	}

	private void setOption1(String name, OptionKind kind, Object... args) {
		String arg = argsToString(args);
		JavacOption option = sharedCompiler.getOption(name);
		if (option == null || !match(kind, option.getKind()))
			throw new IllegalArgumentException(name);
		if ((args.length != 0) != option.hasArg())
			throw new IllegalArgumentException(name);
		if (option.hasArg()) {
			if (option.process(null, name, arg)) // FIXME
				throw new IllegalArgumentException(name);
		} else {
			if (option.process(null, name)) // FIXME
				throw new IllegalArgumentException(name);
		}
		options.add(new Pair<String, String>(name, arg));
	}

	public void setOption(String name, Object... args) {
		setOption1(name, OptionKind.NORMAL, args);
	}

	public void setExtendedOption(String name, Object... args) {
		setOption1(name, OptionKind.EXTENDED, args);
	}

	@SuppressWarnings("static-access")
	private static boolean match(OptionKind clientKind, OptionKind optionKind) {
		return (clientKind == (optionKind == OptionKind.HIDDEN ? optionKind.EXTENDED
				: optionKind));
	}

	public JavacFileManager getStandardFileManager(
			DiagnosticListener<? super JavaFileObject> diagnosticListener,
			Locale locale, Charset charset) {
		Context context = new Context();
		if (diagnosticListener != null)
			context.put(DiagnosticListener.class, diagnosticListener);
		context.put(Log.outKey, new PrintWriter(System.err, true)); // FIXME
		return new JavacFileManager(context, true, charset);
	}

	private boolean compilationInProgress = false;

	/**
	 * Register that a compilation is about to start.
	 */
	void beginContext(final Context context) {
		if (compilationInProgress)
			throw new IllegalStateException("Compilation in progress");
		compilationInProgress = true;
		final JavaFileManager givenFileManager = context
				.get(JavaFileManager.class);
		context.put(JavaFileManager.class, (JavaFileManager) null);
		context.put(JavaFileManager.class,
				new Context.Factory<JavaFileManager>() {
					public JavaFileManager make() {
						if (givenFileManager != null) {
							context.put(JavaFileManager.class, givenFileManager);
							return givenFileManager;
						} else {
							return new JavacFileManager(context, true, null);
						}
					}
				});
	}

	/**
	 * Register that a compilation is completed.
	 */
	void endContext() {
		compilationInProgress = false;
	}

	public JavacTask getTask(Writer out, JavaFileManager fileManager,
			DiagnosticListener<? super JavaFileObject> diagnosticListener,
			Iterable<String> options, Iterable<String> classes,
			Iterable<? extends JavaFileObject> compilationUnits) {
		final String kindMsg = "All compilation units must be of SOURCE kind";
		if (options != null)
			for (String option : options)
				option.getClass(); // null check
		if (classes != null) {
			for (String cls : classes)
				if (!SourceVersion.isName(cls)) // implicit null check
					throw new IllegalArgumentException(
							"Not a valid class name: " + cls);
		}
		if (compilationUnits != null) {
			for (JavaFileObject cu : compilationUnits) {
				if (cu.getKind() != JavaFileObject.Kind.SOURCE) // implicit null
																// check
					throw new IllegalArgumentException(kindMsg);
			}
		}

		Context context = new Context();

		if (diagnosticListener != null)
			context.put(DiagnosticListener.class, diagnosticListener);

		if (out == null)
			context.put(Log.outKey, new PrintWriter(System.err, true));
		else
			context.put(Log.outKey, new PrintWriter(out, true));

		if (fileManager == null)
			fileManager = getStandardFileManager(diagnosticListener, null, null);
		context.put(JavaFileManager.class, fileManager);
		processOptions(context, fileManager, options);
		Main compiler = new Main("javacTask", context.get(Log.outKey));
		return new JavacTaskImpl(this, compiler, options, context, classes,
				compilationUnits);
	}

	private static void processOptions(Context context,
			JavaFileManager fileManager, Iterable<String> options) {
		if (options == null)
			return;

		Options optionTable = Options.instance(context);

		JavacOption[] recognizedOptions = RecognizedOptions
				.getJavacToolOptions(new GrumpyHelper());
		Iterator<String> flags = options.iterator();
		while (flags.hasNext()) {
			String flag = flags.next();
			int j;
			for (j = 0; j < recognizedOptions.length; j++)
				if (recognizedOptions[j].matches(flag))
					break;

			if (j == recognizedOptions.length) {
				if (fileManager.handleOption(flag, flags)) {
					continue;
				} else {
					String msg = Main.getLocalizedString("err.invalid.flag",
							flag);
					throw new IllegalArgumentException(msg);
				}
			}

			JavacOption option = recognizedOptions[j];
			if (option.hasArg()) {
				if (!flags.hasNext()) {
					String msg = Main.getLocalizedString("err.req.arg", flag);
					throw new IllegalArgumentException(msg);
				}
				String operand = flags.next();
				if (option.process(optionTable, flag, operand))
					// should not happen as the GrumpyHelper will throw
					// exceptions
					// in case of errors
					throw new IllegalArgumentException(flag + " " + operand);
			} else {
				if (option.process(optionTable, flag))
					// should not happen as the GrumpyHelper will throw
					// exceptions
					// in case of errors
					throw new IllegalArgumentException(flag);
			}
		}
	}

	public int run(InputStream in, OutputStream out, OutputStream err,
			String... arguments) {
		if (err == null)
			err = System.err;
		for (String argument : arguments)
			argument.getClass(); // null check
		return com.sun.tools.javac.Main.compile(arguments, new PrintWriter(err,
				true));
	}

	public Set<SourceVersion> getSourceVersions() {
		return Collections.unmodifiableSet(EnumSet.range(
				SourceVersion.RELEASE_3, SourceVersion.latest()));
	}

	public int isSupportedOption(String option) {
		JavacOption[] recognizedOptions = RecognizedOptions
				.getJavacToolOptions(new GrumpyHelper());
		for (JavacOption o : recognizedOptions) {
			if (o.matches(option))
				return o.hasArg() ? 1 : 0;
		}
		return -1;
	}

}
